Truck bed liners vary by location, so an accurate estimate is not possible. In general, we see spray on bedliners for a 6 foot bed full size truck anywhere from $525 to $675, but you would need to quote with your local competition to accurately compare. Many shops also charge significantly higher prices for any prep work required, so if your truck bed needs a little work (removing flaking rust or paint, etc.), you may find your cost to be much higher.
Going the DIY route, your typical spray on bedliner kit with spray gun from our store selection runs less than $300 for this size truck. With the do it yourself option, you can also ensure you take the time to do it right and can customize the final product to suit your particular needs.